The present invention relates to a magnetic head slider for recording and reading back information onto and from recording media such as magnetic recording disks with the magnetic head being moved relatively to the recording media.
In recent years, it has been required to reduce the flying height of the magnetic head relative to the magnetic recording medium to 10 nm or less as the magnetic recording disk drives have remarkably been enhanced in recording density.
Generally, a magnetic recording disk drive is composed by combining a magnetic head fixed to a support spring with a magnetic recording disk which is a recording medium. The writing and reading of magnetic records onto and from the magnetic recording disk being rotated is carried out by the magnetic head which is moved relative to the magnetic recording disk by a head access system. Therefore, the unit length per bit is reduced as the plane recording density of the magnetic recording disk is enhanced; viewing from the magnetic head side, this means that it is required to achieve a lower flying height and thereby to read the leakage field efficiently.
In view of the performance of the magnetic head, it is necessary to set the flying height at about 10 nm in the case of a recording density of 100 Gb/in2, and, particularly, the variation of the air bearing surface shape is an obstacle in realizing the above-mentioned flying height. Further, for the purpose of efficient reading of the leakage field, a lower flying height is required at the portion corresponding to the recess amount X1 between a slider substrate and a read element (magnetic head element) disposed via a shield element, since the effective head reading performance is deteriorated if the recess amount X1 is large.
A method of producing the air bearing surface of the magnetic head with such a low flying height generally employs polishing. In particular, if a magnetoresistive (MR) or giant magnetoresistive (GMR) head is used for reading the information from the magnetic recording disks, the element height of the MR or GMR element must be machined with high accuracy. Specific processing methods are described in detail in Japanese Patent Laid-open No. Hei 2-95572 and Japanese Patent Laid-open No. 2000-158335.